The present invention generally relates to fuel water separator systems, and more specifically, but not exclusively, concerns a fuel water separator system in which water from fuel is automatically drained from a fuel water separator that is located on the suction side of a fuel pump in the system.
To protect fuel systems in engines, such as diesel engines, water must be removed from the fuel in order to reduce the risk of corrosion and poor performance in the engine and the other components, resulting from the water. Fuel water separators or filters are generally used to remove water from the fuel, but disposal of the separated water can be problematic. The water is usually stored in a relatively small pump or collection basin in the separator, and the water has to be manually drained through a valve. As a result of the relatively small size of the water pump, routine water drainage is typically conducted by the machine operator, such as a driver, at the beginning of each workday in order to reduce the risk of damage to the fuel system. Manual drainage of the water is not an easy task. Fuel water separators are sometimes located at locations that are generally not easy to access, which in turn makes manual drainage of water inconvenient. Due to environmental concerns as well as reliability reasons, some companies do not want the operator to be required to manually drain the water from the separator.
In response to this problem, automatic water drainage systems have been developed, but most current designs have significant drawbacks. Automatic drainage systems have been proposed that position the fuel water separator at the high pressure side or port of the fuel pump. The high pressure that exists in the fuel at the high pressure side can then be used to purge water from the separator. However, this high pressure fuel water separator design has a number of shortcomings. Typical fuel water separators perform optimally on the suction side (vacuum or low pressure) of the fuel pump. Further, it is desirable that fuel water separators are located on the suction side of the fuel pump so as to protect the fuel pump from damaging water in the fuel because the water in the fuel can create undesirable corrosion and cavitation in the fuel pump. Drainage of water from the suction side of the pump is made difficult by the vacuum that exists at the suction side of the fuel pump. Other types of systems have been developed in which the water is discharged into the air intake of an engine, such into a turbo charger. However, this reintroduction of water as well other contaminants into the air intake reduces the efficiency and life of the engine, and further creates environmental concerns. Additional systems have been developed in which electrical sensors and drain valves are used to drain the water, but since electrical systems tend to increase the number of failure modes, reliability is always a concern with these system. Thus, there is need for a system that automatically removes and drains water from the suction side of the fuel pump without the undesirable effects discussed above.